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Ključne besede: hybrid sol-gel coatings, non-destructive testing, photothermal radiometry, photothermal beam deflection spectrometry, thermal diffusivity, thermal conductivity
Objavljeno v DiRROS: 06.05.2025; Ogledov: 117; Prenosov: 65
Celotno besedilo (1,36 MB)
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Povzetek: Groundwater flow and heat distribution was investigated in the regional karstic-fissured aquifer-aquitard system near Lake Bled in the Slovenian, eastern Julian Alps. The area features thermal springs with temperatures of 19–23 °C which are exploited by abstraction wells. The occurrence of low-temperature geothermal systems, which are common in the Alps, are associated with specific hydrogeological conditions, such as vertical hydraulic connectivity between different geological formations, relatively large elevation differences along flow paths, and the concentrated upwelling of geothermal water to the surface. The occurrence of the low-temperature geothermal field is explained by the presence of a hydraulically conductive fault along with a regional groundwater flow pattern that supports deep groundwater circulation. Hydraulic measurements and temperature data were collected from springs and wells in the area to support the analysis of flow patterns, together with the construction of a basin-scale 2D numerical flow and heat transport simulation. The diverse topographic and geological conditions result in a multi-scale groundwater flow system. The discharge of thermal waters in the Lake Bled area is a consequence of the upwelling of deep groundwater induced by a combination of the ~ 650 m difference in hydraulic head and hydrogeological heterogeneity and anisotropy, related to faulting of the geological formations. In addition, individual flow subsystems were found to significantly affect the natural heat distribution and travel times within the basin-scale system. The study highlights the combination of a basin scale approach taking into consideration local to regional-scale heterogeneities and faults in order to better understand the hydrogeological behaviour of Alpine groundwater systems.
Ključne besede: basin-scale groundwater flow, thermal conditions, carbonate rocks, groundwater recharge, Slovenia
Objavljeno v DiRROS: 02.04.2025; Ogledov: 212; Prenosov: 50
Celotno besedilo (11,21 MB)

Povzetek: Nd-Fe-B-type permanent magnets, containing approximately 30% critical rare-earth elements by weight, are essential components in renewable energy systems (e.g., wind turbines, hydroelectric generators) and electric vehicles. They are also critical for consumer electronics and electric motors in products like energy-efficient air conditioners and home appliances. In light of advancing sustainability goals, the direct reuse of magnets from end-of-life devices offers a promising alternative to energy-intensive and costly recycling methods based on hydro- and pyrometallurgical processes, as well as modern short-loop recycling through hydrogen processing. However, Nd-Fe-B magnets must be demagnetized before they can be extracted from devices. This study explores the effects of thermal demagnetization, performed either in air or a vacuum, on the stability of anticorrosion coatings and the magnetic performance of remagnetized magnets. Corrosion tests were conducted to assess the compatibility of various coatings with thermal demagnetization, identifying those most suitable for future applications involving magnet reuse.
Ključne besede: thermal demagnetization, microstructure
Objavljeno v DiRROS: 28.03.2025; Ogledov: 222; Prenosov: 113
Celotno besedilo (8,10 MB)
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Povzetek: Energy-efficient homes are constructed with a continuous and uniform thermal envelope and are commonly built on top of a thermal insulation (TI) layer that encloses the entire building. Lightweight aggregates such as foamed glass aggregate, expanded clay aggregate, and extruded polystyrene (XPS) insulation boards are commonly used as materials for the TI layer to prevent thermal bridging at the ground floor slab. However, the reinforced concrete slab foundation above the TI layer is susceptible to horizontal sliding during seismic loading. To improve the seismic behavior of buildings founded on TI layers, this study discussed the shear stiffness and damping characteristics of lightweight aggregates and three types of XPS boards through laboratory tests available in the literature. A 2-dimensional numerical analysis is performed, and the corresponding validation results of the simulations are presented. The effect of TI layers on the seismic performance of buildings constructed with TI layers made from these materials is assessed. A comparative analysis of various interface conditions of the TI materials under seismic loading is also conducted. Overall, this research aims to enhance the resilience and sustainability of energy-efficient homes by investigating the impact of TI layers on their seismic performance. The findings provide valuable insights for designing more robust structures that can withstand seismic events.
Ključne besede: energy-efficient buildings, thermal insulation, extruded polystyrene (XPS), finite element analysis, foamed glass aggregate, seismic response
Objavljeno v DiRROS: 21.01.2025; Ogledov: 206; Prenosov: 106
Celotno besedilo (854,84 KB)
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Povzetek: It is necessary to improve the understanding of thermal comfort to reduce energy consumption for heating and cooling in heritage buildings, which are often energy inefficient and where interventions are limited. Personal thermal comfort models based on measurements of environmental conditions and the individual's physiological and subjective responses represent a potential solution to ensure the optimization of existing systems. Past research shows that lighting could impact thermophysiology and subjective perception of thermal conditions, but it is not clear whether the impact is sufficient to make light adaptation an appropriate solution to reduce energy consumption in heritage buildings, where people live and work. The research conducted under realistic semi-controlled conditions in an office environment of an existing building addresses this research gap. The paper presents the first partial simplified analyses and preliminary results of a wider ongoing study, mainly showing a correlation between skin temperature and air temperature and a partially promising effect of light on subjective thermal perception. Our research on the effect of light on thermal comfort does not provide definitive conclusions but rather highlights the need for further investigation in actual heritage buildings.
Ključne besede: heritage buildings, minimal intervention renovation, thermal comfort, light
Objavljeno v DiRROS: 19.12.2024; Ogledov: 300; Prenosov: 156
Celotno besedilo (1,49 MB)
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